\jP Biodiversity fe^HeriUge http://www.biodiversitylibrary.org Transactions of the San Diego Society of Natural History. [San Diego] :The Society,1905- http://www.biodiversitylibrary.org/bibliography/3144 V.18 (1975-1977): http://www.biodiversitylibrary.org/item/28692 Page(s): Text, Page 208, Page 209, Page 21 0, Page 21 1 , Page 21 2, Page 21 3, Page 21 4, Page 21 5, Page 21 6 Contributed by: Harvard University, MCZ, Ernst Mayr Library Sponsored by: Harvard University, Museum of Comparative Zoology, Ernst Mayr Library Generated 26 August 2009 9:10 PM http://www.biodiversitylibrary.org/pdf2/000951600028692 This page intentionally left blank. A living Tesseropora (Cirripedia; Balanomorpha) from Bermuda and the Azores; first records from the Atlantic since the Oligocene William A. Newman and Arnold Ross ABSTRACT.— Tesseropom occupies a central position in the evolution of the Tetraclitinae, and likely the Tetraclitellinae, by virtue of geological age and comparative morphology. Considering the biogeography of the two extant species from the Indo-West Pacific, the genus is apparently favored by the special req\iirements related to perpetuation of insular populations. The more highly evolved genus Tetraclita, on the other hand, is for the most part prevalent on continentfd shores where the opportunities for competitive interactions are greater. Recognition of a new species of Tesseropora from Bermuda and the Azores corroborates the primarily insular nature of the genus and enhances the concept that oceanic iskmds can act as refugia for ancient forms. In consideration of the special adaptations needed by marine organisms to perpetuate their populations on oceanic islands on one hand, and the isolation, ephemerality, short faunal lists and concomitant unbalanced biotas of oceanic islands on the other, one would expect vagile, eurytopic t£ixa, or the descendents thereof, to be disproportionately prevalent on them. Many such t2ixa are early members of lineages having advanced members more conmionly found in centers of distribution frequently contiguous with continental shores, and this is appar- ently the basis for the concept that insular situations can act as refugia for ancient forms. Tesseropora isseli (de Alessandri, 1895: 296), from the Oligocene of Italy, is the oldest known tetraclitid. Pilsbry (1916: 259), when reflecting on the significance of the single row of parietal tubes in the waU of the only extant species of the genus known at the time, remarked " . . . [T. rosea (Krauss, 1848)] is to be regarded as an unprogressive form, which retains characters of the ancestral stock of the genus, elsewhere found [in the Tetrachtidae] only in an early stage of develop- ment", a fact noted earlier by Darwin (1854:336). Since Pilsbry, Tesseropora has maintained a more or less central position in considerations of the evolution of the tetraclitine and tetraclitelline branches of the family (Zullo, 1968:274; Ross, 1969:239; Newman and Ross, 1976:47). From a biogeographic point of view, Tesseropora as previously known would be considered primarily an insular Indo-Pacific genus; T. rosea occurring solely in the southern hemisphere from the southern tip of South Africa to southern Australia, the Kermadec Islands and New Caledonia, and T. wireni (Nilsson- Cantell, 1921: 366) for the most part in the northern hemisphere, from Dar-es-Salaam east, from Chagos Bank to Wake and perhaps the Hawaiian Islands. The counterpart of Tesseropora on continental shores is the more advanced genus Tetraclita, Recognition of an Atlantic Tesseropora, on Bermuda and the Azores, is therefore of considerable significance not only in extending the modem distribution of the genus, but also in corroborating biogeographical inferences that oceanic islands can act as refugia for ancient forms (see Fig. 4). SAN DIEGO SOC. NAT. HIST., TRANS. 18(12):207-216, 24 FEBRUARY 1977 208 perfamily Coronuloidea Leach Family TetracUtidae Gruvel, 1 ubfamily Tetraclitinae Gruvel, Tesseropora Pilsbry, 1916 TesseroDora atlantica n. sl Tetraclita porosa: Verrill, 1901:22 (Bermuda). talactift Henry, (Bermuda); Ross Werner, 1967:70; Ross (Azores Diagno A small (diameter of largest spec, approx. 10mm), white Tesseropora with moderately developed radii having eroded and (or) oblique summits concomitant with a somewhat flaring, toothed orifice; scutal adductoi ridge in line and nearly continuous with articular ridge; intermediate articles oi cirrus VI supporting five pairs of setae; crest of labrum lacking obvious teeth De script white or with a slight pinkish cast; conical; radii and moderately well developed with summits parallel to base; commonly, when eroded, orifice moderately toothed (Fig. 1). Surface of solid radii marked by trans- verse ridges, and of paries by low longitudinal ribs equal to the number of longi- tudinal tubes in the wall. Sheath white, adpressed, continuous with interior surface of paries; region below sheath smooth or marked by reminiscences of small basal denticles in the form of numerous fine ribs. Longitudinal septa normal to inner and outer laminae, forming a single row of irregular tubes (Fig. 2d); one or more incomplete septa may be present on inner surface of outer lamina. None of the specimens available is sufficiently eroded to expose the secondary fiUing of the parietal tubes, but grinding revealed a white filling near the apex. No calcare- ous spines extend from the inner surface of the outer lamina into the parietal tubes as reported for wireni by Henry (1957: 33), and as we have observed in rosea, but older and larger specimens might have them. Basis calcareous, solid, thick, adhering strongly to the wall. Opercular valves white. Scutum with well defined adductor muscle pit and ridge, the curvature of the latter being virtually continuous with that of the articular ridge (Fig. 2b); rostral and lateral depressor muscle crests well defined in larger specimens, apparently increasing in number with age; rostral depressors essentially lacking in small specimens. Tergum with material forming beak undifferentiated from rest of valve and readily broken or worn away; spur furrow open, broad and shallow. Trophi undistinguished except for the lack of conspicuous teeth on the labrum (Fig. 3g). Cirral counts for two specimens from Bermuda follow: I II III IV V VI 12 6 8 9 7 10 14 16 16 18 17 18 Specimen 1 12 8 8 8 8 9 14 14 16 18 16 17 n 6 6 7 7 7 12 16 16 17 16 Specimen 2 12 6 6 7 7 9 12 14 15 17 18 19 1 superfamilial Newman and Ross 209 •» > <^ Figure 1. Tesseropora atlantica n. sp., on an oyster from Argus Tower, Bermuda. The third cirrus is normal in form (rami not antenniform); supporting three types of bipectinate setae (Fig. 3c-e), the heaviest (card) being rarely observed; surfaces of the lesser curvature eirmed with short, curved spines or denticles (Fig. 3f). Intermediate articles of cirrus VI bearing five pairs of setae with occasional pairs or small clusters of short bristles between major pairs (Fig. 3b). The intromittant organ is normal. B B Figure 2. A, Right tergum and scutum of Tesseropora wireni (Nilsson-Cantell) from Wake Island (type locality of T. w. pacificoy approx. 20mm basal diam.); and B, of T. atlantica n. sp. fr< Bermuda (type, approx* 11mm diam.); C, D, and E. basal margins of parietes of T. wireni, T. atlantica •111 and very young Tetraclita stalactifera (Lamarck), respectively. 210 B 1 . 2 111 --J 1 .Inn iCDEFA' iHI I.OSm I.OSm Figure 3. A^, intermediate articles of sixth cirrus in Tesseropora wireni (approx. 20mni diam.) and A , portion of an intermediate article of the sixth cirrus in T. wireni (approx. 40mm diam.) from Wake I., the latter showing the increase in number of small spines below each of the larger two pairs of setae. B-I Tesseropora atlantica n. sp.: B, intermediate articles of sixth cirrus; C, D, and E, specialized setae; F, spines found on the third cirrus; G, labrum (right palp deleted); H, first maxilla, I, mandible. Type material .—Gxxmet Rock, Bermuda (type locality), intertidal with Chthamalus and Catophragmus (see Henry, 1958); USNM type); BM(NH) 1976.1281 (paratype) [USNM ace. no. 827 (type lot; USNM Argus Tower, southwest of Bermuda, subtidal (2-3m), dried. NM Lopha frons), W 168473. UrzeUna 1976, BM(NH) Azores Expedition (see Baker Reference ;e, Azores, Southward BM(NH) makin material .—One often must rely on published descriptions in _ ments on the distinctiveness of a species. By good fortune Tesseropora is a small genus, and we had comparative materials in our collections of the other species upon which to base our analysis. Tesseropora wireni (Nilsson-Cantell): Wake Island [type locality of T. w. pacifica (PUsbry)], numei^ous large speci- mens with Euraphia intertexta (Darwin), 1854, R. McFarlan coll., 27 Dec. 1964. Ulupau, Hawaii, numerous small specimens from 6" pipe of seawater system. Burch leg., 28 Sept see discussion Moen Island, Truk, CaroUne Islands, a single small speci men from the underside of an intertidal coral boulder resting on sand, W. A. New- man Dublon Channel, Truk, CaroUne Islands, numerous small specimens oi from underside of buov, W. A. Newman coll., June, 1956 (see Newman pi. 20, fig. 1). Table 1. Distinguishing characteristics of extant species of Tesseropora. 211 Color: 1-wall Intermediate Species Form and size 2-sheath Radu Parietal aegmente m Sfiiling tubes Scutum Labrum Cirrus III Cirrus VI 4-valves Steeply corneal 1- white adductor apparently occasionally five pairs when young; 2- white ridge in without armed with of setae atlantica ? when old; 3-white moderately in single line with conspicuous heavy bipecti- per article approx. 10 mm 4 -white wide row articular teeth nate setae in basal ridge (cards) diameter adductor with several armed with three pairs of 1-white ridge teeth on numerous setae per m 2-dirty white ditto overlapping each side of cards article, num- rosea Steeply coni- tinted pink ditto articular shallow erous short cal; up to 3-usu£dly ridge notch setae in dense 30mm pink 4-white 1-white armed with bunches below two major prs. as rosea l>ut Steeply conical 2-usuaUy into sec- bipinnate but with a few when young; dark red- extremely ondary and ditto ditto not bipectinate short setae in wireni low when old; brown narrow to tertiary setae (cards) groups below up to 40mm 3-usuaUy pink lacking rows bas- aUy two major pairs 4-white Kwajalein Atoll, Marshall Islands, Carmarsel Expedition (CRS-325), inter- tidal, on iron piling, numerous specimens with E. intertexta, W. A. Newman coll., 2 April 1967. Ulul Island, Namonuito Atoll, Caroline Islands, Carmarsel Expedition (CRS-307), several specimens in Heliopora, with Lithoglyptes wilsoni Tomlinson, 1969, 10m, W. A. Newman coll., 15 Feb. 1967. Port of Palau, Arakabesan Passage near Perir}^! Island, Caroline Islands, in Heliopora, Seto Marine Biological Laboratory no. 81, F. Hiro coll., 1934 (see Hiro, 1935: 5; the collection studied consists of some fragments of Tesseropora, and several complete specimens of a pyrgomatid imbedded in the cored). Tesseropora rosea (Krauss): Gerroa (south of Port Kembla), New South Wales, Australia, on mid-tidal rocks, E. Pope coll., 2 April 1963. Bouvail-Baie des Tortues, New Caledonia, a single large specimen, dried, from a rock, J. C. Plaziat coll., 5 Nov. 1973. DISCUSSION Only one species referrable to Tesseropora (Conia rosea Krauss) was known when Darwin (1854) published his incomparable monograph on the sessile barnacles. The second, T. isseli (de Alessandri, 1895), from the Oligocene of Italy, while morphologically close to rosea, is known only by the wall and need not con- cern us here. A third species, wireni, was described by Nilsson-Cantell (1921: 366), followed by wireni pacifica (Pilsbry, 1928: 312) and wireni africana (Nilsson- Cantell, 1932: 14). Henry (1957: 33) elevated pacifica to specific rank. We believe, as Zullo (1968) seemingly did, that there is presently insufficient data to dis- tinguish pacifica from wireni at the specific or the subspecific level, and believe the same is true of africana. Therefore, we tentatively treat living Tesseropora as containing but two taxa, rosea and wireni. The new species, T. atlantica, can be distinguished from both rosea and wireni by a number of characters (Table 1), the most obvious being the alignment of the scutal adductor ridge with the articular ridge rather than passing well in- ward of it (compare Figs. 2b and 2a), and the intermediate segments of cirrus VI bearing five rather than three pairs of setae (compare Figs. 3b and 3a). Tesseropora rosea, known from New South Wales, South Africa and New Caledonia, differs from mature wireni in retaining a single row of parietal tubes throughout life. While secondary riblets develop on the interior of the outer lamina, as noted by 212 40* — E 180" W 140' Tesseroplax 60' 40 O 20' 0' -20' 40' 140' 20 E 180' W 140' Figure 4. Distribution of Tesseropora spp. and the closely related Tesseroplax unisemita (Zullo, 1968). The latter is known only from Pliocene sediments in the Gulf of CaUfomia (cf. Ross, 1969). The other significant fossil record is that for Tesseropora isseli from the Oligocene of Italy, The Indo-West Pacific species, T rosea and T wireni, while morphologically distinct, are more closely related to each other than to T. atlantica from Bermuda and the Azores. At the present level of our knowledge the taxonomic status of the so-called subspecies of T. wireni cannot be sustained. The assignment of the Hawaiian form to T wireni is questioned herein. Darwin (1854: 336), they are normal to the surface and thereby fail to join the primary septa to form secondary tubes. Young wireni, and it is young specimens that are apparently most commonly collected and described, also have a single row of essentially square parietal tubes, but with growth the longitudinal septa join some of the riblets on the interior of the outer lamina, singly or in pairs, leading: to the dendritic pattern of the septa separating the secondary tubes formed in Although we have not observed secondary in atlantica, Henry (1958: 224) noted a few in the rostrum of the largest specimen IIU re like she examined. The appearance of large, eroded atlantica may appear that of wireni than that of rosea. Young, uneroded rosea were described by Darwin (1854: 323), and apparently the best character that might be used to distinguish them from young wireni would be moderate to well developed radii in the former. It follows that young uneroded rosea cannot be distinguished from atlantica, at the present state of our knowledge, since both have radii. The only characters %%l% iwn that will separate them are the interiors of the scuta, the pinkish rather than white filling of the parietal tubes, and the nature of the cirri described above. The specimens of Tesseropora from Hawaii are not tygicsl of wireni. All available are small, less than 3 mm in basal diameter, and therefore they had not contained larvae and comoleted their develooment ually mature (see discussion of larvae below). This Hawaiian material is similar to the wireni studied •]|| in having much reduced radii and in having a toothed labrum, but the adductor ridge of the scutum is closer to being in line with the articular ridge (similar to atlantica), the sheath is white (Pilsbry, 1928: 313, noted that the sheath of wireni ranges from Prussian blue to white, but his material included specimens from Necker Island in the Hawaiian Archipelago as well as from Wake Island), the cirral coimts are lower, cirrus III has bipectinate (cards) as well as bipinnate setae, and the inter- mediate segments of cirrus VI bear three, four or five pairs of setae (on the same ramus), but commonly four, a niunber intermediate between that found in atlan- tica. gmd wireni and rosea. The differences noted here make it difficult to assign this material to wireni for, if consistent, they would be sufficient to allow c propose the Hawaiian form as a new species. However, such a decision will to await further studv. 213 Both rosea and wireni can attain basal diameters approaching 40 mm, and in most large specimens the outer lamina of the shell is all but completely eroded, exposing the generally pinkish, more resistent material lining the interior of the parieted tubes. In a specimen of rosea from New Caledonia most of these run con- tinuously from the apex to the base, but a few can be observed on the exterior, beginning more than halfway down the wall rather than at the apex, and this indi- cates, although there is predominantly a single row of tubes in the wall, a few supernumerary ones occasionally develop. Zullo (1968: 272) noted comparable development in this species from southeast Austredia. In appe£U"8ince, wireni is comparable, but many more of the pillars exposed by erosion, other than the primary ones, begin at varying distances down the shell below the apex. Thus, the general ribbing appears finer because of the more numerous development of secondeiry parietal tubes. None of the specimens of atlantica is sufficiently eroded to expose the pillars. It is perhaps significant that wireni, although ranging from East Africa to Wake Island and perhaps to Hawaii, appears to be a relatively rare species. Also, most of the material described has been of relatively young uneroded specimens, up to but generedly smedler than 15 mm or so in diameter. One is led to suspect the same thing may be true for atlantica — the specimens on hand are relatively young individuals and the species is likely not confined solely to Bermuda and the Azores. « — Verrill (1901: 22) identified a Bermudan form as Tetraclita porosa (= squamosa). Although we cannot prove he had Tesseropora rather than Tetraclita s. s., it does seem highly likely because he stated, "This is the common, small, sessile barnacle foimd on the rocks between tides, with the general appear- ance of some species of Balanus". Species of Tetraclita, however, are generally relatively large, and it is the erosion of the outer lamina of the shell, exposing the colored infilling of the parietal tubes, that gives them the characteristic tetracUtid appearance. On the other hand, atlantica is known as a small species, and in being uneroded it does have a somewhat balanid appearance. In any event, his identifi- cation apparently led Henry (1958: 224) to consider the Stephensons' material to be T squamosa stalactifera, the only "subspecies" of the squamosa complex known from the Caribbean. The single row of tubes in the wall did not invaUdate this conclusion for, as Darwin (1854: 323) noted, in very young specimens of Tetraclita there is only a single row of tubes (Fig. 2e). During growth, these are added to by bifurcation of the septa at the outer lamina very early in Tetraclita and Tetraclitella, quite a little later in wireni and possibly atlantica, and hardly at all in rosea. It is important to note that in Tetraclita the septa forming the single row of tubes are at angles other than normal to the inner lamina, but in Tesser- opora they are normal or essentially normal (compare Figs. 2c and 2d with 2e). This and the presence of a calcareous basis in the latter serves to distinguish the two genera. The development of radii, a tubiferous wall and a strong calcareous basis would appear to be fundamental to the Tetraclitidae, all three being the principal advances in the shell made over the bathylasmatid (ancestral) level of organization (Newman and Ross, 1976: 20). Radii greatly strengthen the waU, important in the surf zone (Darwin, 1854: 56; Barnes, Read and Topinka, 1970: 82). A tubiferous wall, especially when secondarily filled, places an additional barrier to erosion and boring organisms (Ross, 1970: 9; Newman and Ross, 1971: 159). A calcareous basis conveys an advantage in forming a strong attachment (Newman, Zullo and Wainwright, 1967: 170) and in retarding desiccation in intertidal forms, especially in the tropics where porous reef limestones are common ( Southward and Newman, in press). Tesseropora has these advanced features. But the most successful 214 tetraclitid today, in terms of being an abundant intertidal dominant, is Tetraclita. The genus has carried the filled tubiferous wall to the extreme, and perhaps the great thickness achieved has allowed it to give up radii, but why it has also given up a calcareous basis is an enigma, unless it has gained a degree of limited motility, as was demonstrated for Semibalanus balanoides by Crisp (1960: 1208). primarily an insular species, is known to carry tracli imbryonic development through to the cyprid stage, passing the naupliar Cantell Ross, 1961: 211). Cyprid larvae are are not known to remain long in the incapable of feeding and, because they also plankton, they are not likely propagules for long-range disperal (Newman and Tomlinson, 1974: 208). The direct production of the non-feeding stage in diyisa could be an adaptation to the relatively sterile waters of most oceanic situations, but because most balanomorphans of such regions apparently have nauplii, this could be only part of the reason, another being the selection for mechanisms that favor maintaining populations on isolated oceanic islands too distant to be regu- larly reached from elsewhere by ordinary means. Species having a tendency to suppress the nauplius would thereby be likely candidates for maintaining popu- lations on isolated insular situations. It is interesting therefore to note that the larvae of Tesseropora from Hawaii just mentioned are released as cyprids, and it will be interesting to see if the life histories of other populations or species of the are so modified may aid in maintaining insular populations, such populations would appear to have removed themselves from the list of potential island colonizers by larval propagules. Furthermore, because islands are ephemeral in terms of geological time relative to continental shores, the time to extinction of such lineages would be substantially shortened. However, this problem can and apparently has been circumvented because some sedentary species with short range larvae have achieved and apparently maintain distributions over great expanses of open water. So far as divisa is concerned, and the likewise virtually cosmopoUtan Balanus trigonus, transport of adult gul more so by other organisms, seems likely. One of us (W.A.N.) has found adults of the former washed ashore on Majuro Atoll m the Marshall Islands attached to the shell of the pelagic barnacle Lepas, and of the latter, attached to the shell of the whale barnacle Coronula. These species there- fore have the potential of being transported great distances as adults, and this may explain their virtually cosmopolitan distributions in the warm seas of the world. known to form an obligate commensal relationship individuals of some species are foimd on other organisms, the most notable being wireni, which occurs embedded in the blue coral Heliopora. If the history of the genus continues and it is eventually completely replaced as a free-living form, conceivablv wireni could Dersist as an obligate commensal. ACKNOWLEDGMENTS We thank Alan J. Southward, Marine Biological Association of the United Kingdom, for bringing this problem to our attention and for providing specimens from Bermuda and the Azores. We would also like to thank T. E. Bowman, National Museum of Natural History, William K. Emerson, American Museum of Natxiral History, W. D. Hartman, Yale Peabody Musuem and W. E. Sterrer, Bermuda Biological Station for their attempts to locate voucher specimens from Bermuda collected either by Verrill or others near the turn of the century; and G. A. Boxshall, British Museum (Natural History) for attempts to locate material from the Azores. Thanks are also due Huzio Utinomi, who kindly arranged for the loan of specimens from the Seto Marine Biological Laboratory, Beatrice L. Bxirch for the somewhat enigmatic specimens from Hawaii, and Gayle Kidder for technical assistance and preparation of the figures. Work supported , in part, by the National Science Foundation (DEB-7517149). REFERENCES 215 Baker, I. H., 1967. Cirripedia m, Chelsea College Azores Expedition, 1965, Final Report: 46-47. University of London. Barnard, K. H., 1924. Contributions to the crustacean fauna of South Africa. No. 7. Cirripedia. Annals South African Museum 20: 1-103. Barnes, H., R. Read and J. Topinka. 1970. The behaviour on impaction by solids of some common cirripedes and relation to their normal habitat. Journal of Experi- mental Marine Biology and Ecology 5(1): 70-87. Crisp, D. J„ 1960. Mobility of barnacles. Nature 188(4757): 1208-1209. Darwin, C, 1854. A Monograph on the subclass Cirripedia with figures of all the species. The Balanidae, the Verrucidae, etc, Ray Society, London, 684pp. de Alessandri, G., 1895. Contribuzione alio studio dei Cirripedi fossili d'ltalia. Societa Geologica Italiana, Bollettino 234-314. Edmondson, C. H., 1946. Reef and shore fauna of Hawaii. Bemice P. Bishop Museum Special Publication 22. 381pp. Endean, R., W. Stephenson and R. Kenny, 1956. The ecology and distribution of intertidal organisms on certain islands off the Queensland coast. Australian Journal of Marine and Freshwater Re- search 7(3): 317-342. Foster, B. A., 1974. The barnacles of Fiji, with observations on the ecology of barnacles on tropical shores. Pacific Science 28(1): 35-56. Henry, D. P., 1957. Some littoral barnacles from the Tuamotu, Marshall, and Caro- line Islands. Proceedings U.S. National Museum 107(3381): 25-38. Henry, D. P., 1958. Intertidal barnacles of Bermuda. Journal of Marine Research 17: 215-234. inmiensalism between the cirripeds and other animals. Ecologi- cal Review, Sendai 2(1): 58-65. , F., 1937. Cirripeds of the Palao Islands. Palao Tropical Biological Station Studies 1: 37-72. Krauss, F., 1848. Die sudafrikanischen Mollus- ken. Ein Beitrag zur Kenntniss der MoUusken des Kap-und Natal-landes und zur geographischen Verbreitung dersel- ben, mit Beschreibung und Abbildimg der neuen Arten. Stuttgart. Macnae, W. and M. Kalk (eds.), 1969. A natural history of Inhaca Islands, Mozambique. Witwatersrand University Press, Jo- hannesburg, South Africa. 163pp. Matsuda, C, 1973, A shoreline survey of free- living intertidal barnacles on the island of Oahu, Hawaii. 60pp. Unpublished Newman, W. A., 1960. The paucity of inter- tidal barnacles in the Tropical Western Pacific. VeUger 2(4): 89-94. Newman, W. A. and A. Ross, 1971. Antarctic Cirripedia. Antarctic Research Series 14. 257 pp. American Geophysical Union. Newman, W. A. and A. Ross, 1976. Revision of the balanomorph barnacles; including a catalog of the species. San Diego Society of Natural History, Memoir 9. Newman, W. A. and A. Ross, in press. Super- families of the Balanomorpha. Crustaceana. Newman, W. A. and J. T. Tomlinson, 1974, Ontogenetic dimorphism in Lithoglyptes (Cirripedia: Acrothoracica). Crustaceana 27(2): 204-208. Newman, W. A., V. A. Zullo and W. A. Wain- wright, 1967. A critique on recent con- cepts of growth in Balanomorpha (Cirripedia, Thoracica). Crustaceana 12(2): 167-178. Nilsson-Cantell, C. A., 1921.Cirripeden-Studien. Zur Kenntnis der Biologie, Anatomie und Systematik dieser Gruppe. Zoologiska Bidrag Uppsala 7:75-395. Nilsson-Cantell, C. A., 1932. Neue Balaniden aus Sud-und Ost-Afrika in dem Berliner Museum. Arkiv fur Zoologi 24A(6):1-18. Pilsbry, H. A., 1916. The sessile barnacles (Cirripedia) contained in the collections of the U.S. National Museum; including a monograph of the American species. Bulletin of the U.S. National Museum 93:1-366. Pilsbry, H. A., 1928. Littoral barnacles of the Hawaiian Islands and Japan. Proceed- ings Academy Natural Sciences Phila- delphia 79: 305-317. Pope, E., 1945. A simpKfied key to the sessile barnacles found on the rocks, boats, wharf piles and other installations in Port Jackson and adjacent waters. Records of the Australian Museum 21(6): 351-372. Ross, A., 1961. A new cirriped from the Hawaiian Islands. Crustaceana, 2(3): 209-212. Ross, A., 1962. Results of the Puritan- American Museum of Natural History Expedition to western Mexico. No. 15. The littoral American balanomorph Cirripedi, Museum Novitates 2084: 1-44. Ross, A., 1968. Bredin-Archbold-Smithsonian Biological Survey of Dominica. 8. The intertidal balanomorph Cirripedia. Pro- ceedings U.S. National Museum 125 Ross Zoology Hawaii (3663): 1-22. A., 1969. Studies on the Tetraclitidae (Cirripedia: Thoracica): Revision of TetracUta. Transactions San Diego Society of Natural History 15(15): 216 237-251. Ross, A., 1970, Studies on the Tetraclitidae (Cirripedia: Thoracica): A proposed new genus for the austral species Tetraclita purpurascens breviscutum. Transactions San Diego Society of Natural History 16(1): 1-12. Smith, W. A.. 1971. Crustacea: Cirripedes from Diego Garcia. Atoll Research Bulletin 149:103. Southward, A. J. and W. A. Newman, in press. Aspects of the ecology and biogeography of the intertidal and shallow-water balanomorph Cirripedia of the Caribbean and adjacent sea-areas. CICAR-II Sym- posium, Caracas, Venezuela, July 12-16, 1976. VerriU, A. E., 1901. Additions to the fauna of the Bermudas from the Yale Expedition of 1901. with notes on other species. Transactions Connecticut Academy of Arts and Sciences 11(1): 15-62. Werner, W. E., 1967. The distribution and ecology of the barnacle Balanus trigonus. Bulletin of Marine Science 17(1): 64-84. ZuUo. V. A., 1968. Tesseropora Pilsbry (Cirripedia, Thoracica) from the Pliocene California 15(3): 272-274. Scnpps f Oceanography A-002, La JollOy California 92093 and Natural History Museum, Box 1390, San Diego, California 92112. Contribution No. 692 from the Bermuda Biological Station for Research, Inc. Contribution of the Scripps Institution of Oceanography, new series.